二相流理论在光整加工技术中的应用研究

阐述了二相流的基本理论，探讨了其在光整加工技术中的应用，介绍了二相流基本理论在光整加工技术中的3种应用工艺。     

Effects of injection temperature on the jet evolution under supercritical conditions

A nitrogen jet with subcritical and supercritical injection temperatures injected into a supercritical environment, in which both the pressure and temperature exceed those of the thermodynamic critical state, has been investigated numerically using large-eddy simulation technique. The effects of the injection temperature on the flow evolution are studied. We find that the jet surface is more unstable with the instability waves growing up and rolling into a succession of ring vortices for supercritical injection temperature, and the jet surface is nearly straight with the strong density stratification suppressing the development of the instability waves for subcritical injection temperature. With increasing injection temperature, the spatial growth rate of the surface instability wave strengthens and the frequency of the most unstable mode increases. This behavior is of importance in enhancing the fluid mixing effect. The results obtained in this study provide physical insight into the understanding of fundamental mechanisms of the jet evolution under supercritical conditions.     

Visualization of Coherent Structures in Acoustically Forced, Gas-Particle Turbulent Round Jet

To show the effects of the particles and forced disturbances on the instantaneous large-scale vortex structures in a gas-particle round jet, coherent structures in gas-particle turbulent round jets were investigated experimentally by flow visualization. The 45-μm and 350-μm diameter glass beads were used as the particles in the experiments. An acoustic speaker was used to introduce velocity perturbations at the jet exit. The Strouhal number based on the nozzle diameter, exit velocity, and forcing frequency was varied from 0,1 to 0.9. The Reynolds number was 9400. The coherent structures were visualized in unforced and forced single-phase jet flows and unforced and forced particle-laden jet flows with different diameter glass beads. The experimental results show that the particles have significant effects on the gas phase coherent structures. The coherent structures are controlled by the large 350-μm diameter particles, while the structures are mainly dominated by the forced disturbances in the flows with 45-μm diameter particles.     

《金属工艺学》教学改革探索与实践

高职教育的人才培养模式,要求我们必须对《金属工艺学》课程的教学内容、教学方法以及考核评价方法进行改革。勤于思索,勇于实践,是改革成功的基础。     

A THEORY ON TEA-POT EFFECT

In this paper exit.bend angle(tea-pot effect)has been analysed theoretically based on thebasic)aw of hydromechanics.It was proved that it is the transverse shear stress that causes exitbend angle while the bending direction is along with the resultant force of the shear stresses andthe magnitude of the exit angle is directly proportional to the resultant force.The equation re·lating exit bend angle with the resultant force was set up and experiment verification of theequation was carried out with rational agreement to theoretical results.     

高压射流雾化性能实验分析

利用高压射流雾化系统，观测了不同条件对射流雾化形态的影响，并对射流雾化规律进行了分析。其结果参于再生式液体发射药火炮弹道性能稳定性控制具有指导意义。     

德士古渣油气化炉冷态浓度分布的测试与研究

采用双通道喷嘴，在直径1000mm和高4000mm的大型冷模装置上，对德士古渣油气化炉冷态浓度分布进行了测试和研究，考察了喷嘴中心与环隙射流动量比对宏观混合过程的影响，给出了无因次径向浓度分布，无因次最大浓度和混合分数的轴向衰减以及无因次浓度半半径沿轴向的变化规律。     

喷气纺纱条动态气圈的转速与成纱强力的关系

喷气纺纱是利用旋转气流作用推动纱条形成气圈运动,使头端自由纤维加捻成纱。本文采用本组研制的纱条气圈转速仪对喷气纺纱纱条动态气圈的转速进行了测试,并就改变加捻成纱过程中的第一喷嘴和第二喷嘴的气圈转速,探讨其与成纱强力的关系。     

三坐标动态切削力系数的研究

本文采用随机激振技术和离散权函数系列的辨识方法,着重研究了三坐标重叠切削条件下动态切削力系数的建模辨识和切削速度V、进给量S、切削深度h三参数对动态切削力系数的影响.